US Patent Application Early Publication No. US20170206868A1, U.S. Pat. No. 8,624,097B1 and US Patent Application Early Publication No. US20150059555A1 disclose a cajón percussion instrument. The cajón percussion instrument is composed of a mallet assembly, a pedal assembly and a sleeve. Two ends of the sleeve are fixed to the mallet assembly and the pedal assembly, respectively. A cable passes through the sleeve. Two ends of the cable are connected to the mallet assembly and the pedal assembly, respectively. The cable is pulled by stepping on the pedal assembly, and the mallet assembly is pulled by the cable to strike the cajón. However, the sleeves of the above-mentioned three cajón percussion instruments are arranged in a curved shape and have a considerable curvature, so the cable passing through the sleeve will be flexibly deformed along the sleeve. The cable is in contact with the inner wall surface of the sleeve, leading to a significant increase in the frictional resistance of the cable. When the user steps on the pedal assembly to pull the cable to drive the mallet assembly to strike the cajón, the user needs to exert a great force to pull the cable. After a period of time, the user may have aches in the foot.
Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.